Dave919, I love those little opportunities like that, I can't count the times Iv'e tickled my wife under the same circumstances as your story, right down to the black suit and laying on the couch.
Many times my wife will come home from work for lunch and take her conference calls while laying on the couch and she always asks me to massage her feet while she relaxes but after awhile the temptation is too great and I have to tickle her softly.
She usually just glares at me and tries not to laugh while I softly tickle her feet and I know a couple of times other people on the call have heard her laugh.
I can't do this though while she's talking to her sister on the phone because to get me to stop, she'll try to embarass me by saying out loud "quit tickling my feet you weirdo" and then she'll laugh because I'll get frustrated but I know it's no big deal to her sister because my brother in law always does the same thing her.